WO2017087638A1 - Vanne à autorégulation basse pression et basse énergie - Google Patents

Vanne à autorégulation basse pression et basse énergie Download PDF

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Publication number
WO2017087638A1
WO2017087638A1 PCT/US2016/062474 US2016062474W WO2017087638A1 WO 2017087638 A1 WO2017087638 A1 WO 2017087638A1 US 2016062474 W US2016062474 W US 2016062474W WO 2017087638 A1 WO2017087638 A1 WO 2017087638A1
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WO
WIPO (PCT)
Prior art keywords
pressure
flow
flow rate
tube
self
Prior art date
Application number
PCT/US2016/062474
Other languages
English (en)
Inventor
Ruo-Qian WANG
Amos G. WINTER
Abhijit Bhaskar JOSHI
Original Assignee
Massachusetts Institute Of Technology
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Massachusetts Institute Of Technology filed Critical Massachusetts Institute Of Technology
Priority to US15/320,877 priority Critical patent/US10254770B2/en
Publication of WO2017087638A1 publication Critical patent/WO2017087638A1/fr
Priority to US16/376,574 priority patent/US10761545B2/en

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Classifications

    • G—PHYSICS
    • G05—CONTROLLING; REGULATING
    • G05D—SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
    • G05D7/00—Control of flow
    • G05D7/01—Control of flow without auxiliary power
    • G05D7/0106—Control of flow without auxiliary power the sensing element being a flexible member, e.g. bellows, diaphragm, capsule
    • G05D7/0113—Control of flow without auxiliary power the sensing element being a flexible member, e.g. bellows, diaphragm, capsule the sensing element acting as a valve
    • A—HUMAN NECESSITIES
    • A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
    • A01G—HORTICULTURE; CULTIVATION OF VEGETABLES, FLOWERS, RICE, FRUIT, VINES, HOPS OR SEAWEED; FORESTRY; WATERING
    • A01G25/00—Watering gardens, fields, sports grounds or the like
    • A01G25/02—Watering arrangements located above the soil which make use of perforated pipe-lines or pipe-lines with dispensing fittings, e.g. for drip irrigation
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
    • F16L55/00—Devices or appurtenances for use in, or in connection with, pipes or pipe systems
    • F16L55/04—Devices damping pulsations or vibrations in fluids
    • F16L55/045—Devices damping pulsations or vibrations in fluids specially adapted to prevent or minimise the effects of water hammer
    • F16L55/05—Buffers therefor
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
    • F16L55/00—Devices or appurtenances for use in, or in connection with, pipes or pipe systems
    • F16L55/04—Devices damping pulsations or vibrations in fluids
    • F16L55/045—Devices damping pulsations or vibrations in fluids specially adapted to prevent or minimise the effects of water hammer
    • F16L55/055—Valves therefor

Definitions

  • This invention relates to a self-regulating valve allowing independent control of flow rate and activation pressure for use in an irrigation system.
  • Drip irrigation is a means of reducing the water required to irrigate by up to 60%, and it has been shown to be a successful development strategy enabling poor farmers to rise out of poverty by growing more and higher value crops.
  • the barrier to drip irrigation achieving large-scale dissemination is the cost of the pump and power system.
  • the power consumption is equal to the product of flow rate and pressure. For a given farm, the flow rate is
  • the primary opportunity to reduce the power consumption is to lower pumping pressure.
  • Pressure compensation is a means of maintaining a constant flow rate from a drip emitter under varying applied pressure - an important feature for a low pressure dripper network where pressure from the pump to the end of the line can vary by a factor of three.
  • the self-regulating valve of the invention includes a static pressure chamber and an elastically collapsible tube supported within the static pressure chamber.
  • static pressure is meant a fluid maintained at a selected static pressure in the chamber.
  • a flow restrictor is in fluid communication with the collapsible tube inside the static pressure chamber and piping is provided connecting a source of pressurized liquid both to the flow restrictor and to an opening into the static pressure chamber, whereby flow rate through the valve remains substantially constant with variations in pressure of the pressurized liquid.
  • the flow restrictor is a needle valve.
  • Fig. 1 is a graph of flow rate against driving pressure illustrating the activation pressure.
  • Fig. 2a is a cross-sectional view of a prior art Starling resistor.
  • Fig. 2b is a cross-sectional, schematic illustration of an improved Starling resistor architecture as disclosed herein.
  • Figs. 3a and 3b are graphs of flow rate against pressure.
  • Fig. 4a is a graph of k v versus flow rate.
  • Fig. 4b is a graph of flow rate against pressure showing that changing resistance of the needle valve allows for control of the flow rate independent of the activation pressure.
  • Fig. 5a is a graph of flow rate against pressure for an embodiment of the invention.
  • Fig. 5b is a graph of flow rate versus pressure with variations in a tube property such as tube wall thickness.
  • Figs. 6a and 6b are graphs of flow rate against pressure for tube length variations.
  • Fig. 7a is a graph showing a comparison of activation pressures from experimental results and from theory.
  • Fig 7b is a graph comparing limited flow rates from experimental results and from theory.
  • a novel design of a low-energy, passive self-regulating pressure compensating valve with a single pressure source is disclosed for drip irrigation.
  • Pressure compensation is a mechanism that sustains a flow at constant flow rate regardless of the driving pressure.
  • the minimum driving pressure that initiates the pressure compensation is called the "activation pressure" (Fig. 1).
  • Activation pressure is key to pumping power - since the power is proportional to the product of flow rate and pressure, the activation pressure dictates the minimum maintaining pressure of the system and thus determines the lowest pumping power, given a fixed flow rate.
  • this design can reach an extremely low activation pressure using a flexible tube architecture.
  • a Starling resistor is a device consisting of an elastically collapsible tube mounted inside a static pressure chamber as shown in Fig. 2a [1].
  • the experimental setup included a pressure supply, a measurement system and a modified Starling resistor (Fig. 2b).
  • the whole system was driven by static pressure from a pressure tank, which was pressurized by compressed air and controlled by a pressure regulator.
  • the pressure could range from 0 to 200 kPa (0 - 2 bar).
  • the pressure tank was connected to the Starling resistor 10 through a high-resolution rotor flow meter 12
  • a branch was installed downstream of the flowmeter to pressurize the Starling resistor 10 chamber and a pressure transducer 14 (Setra model 209 with a measurement range of 0-172 kPa) was installed at the branch to monitor the pressure. Since the water could be treated as static in the branch and in the chamber, the measurement of the transducer was equal to the pressure at the T-junction point at the beginning of the branch, which was also equal to the pressure in the chamber.
  • the pressure transducer and the flow meter were connected to a data logger to record the real-time signal with a sampling rate of 2000 Hz.
  • the flow limitation results are presented in terms of flow rate versus driving pressure.
  • the pressure is the reading from the pressure transducer 14 and represents the pressure difference from the pressure chamber to the atmosphere.
  • the pressure difference from the end of the unsupported section to the outlet is negligible compared to the pressure change along the unsupported section, so the pressure measurement from the transducer can be considered as the transmural pressure applied at the end of the unsupported tube.
  • Two flow limitation modes are found and shown in Figs. 3a and 3b.
  • the results in the figure are original data for a single trial. Each result includes two curves: the solid curve was obtained in the pressurizing scenario, and the dash line is from the depressurizing scenario.
  • the pressure variation process is also shown by the arrows in the figure. The difference between them is due to the hysteresis stemming from the nonlinear tube deformation and the nonlinear flow dynamics.
  • Mode 2 in Fig. 3b is more complex, and was found in Cases C and D. Similar to Mode 1 , the flow rate initially increased with the square root of the pressure until reaching P a , with no deformation in the tube cross-section. After the peak, the flow rate dropped gradually, while the tube was steadily squeezed and the cross-sectional area decreased until the flow dropped to the lower limit of the flow meter. In the depressurizing scenario, the flow rate increased abruptly and overshot the pressurizing scenario. The difference in flow rate depended on how quickly the pressure was decreased. The flow rate then fell back to the value of the pressurizing scenario when the oscillation decayed. It followed a lower route to reach the zero point due to hysteresis. We observed that the flow limitation behavior was dependent To ensure the
  • the present experiment employed a novel way to induce a transmural pressure by introducing a needle valve, rather than a separate external pressure.
  • the resistance coefficient of the valve was determined by measuring its flow rate at different driving pressures (Fig. 4a), i.e. ⁇ where P v is the pressure drop over the valve and u v is the mean velocity at the inlet of the valve.
  • Fig. 4a driving pressures
  • FIG. 4b Another observation about Fig. 4b is that the flexible tube suddenly fully closed at the highest pressure, cutting off the flow. This stopping pressure decreased with smaller valve openings.
  • the flow rate had a spike from zero before a flow was initiated, at which point the flexible tube had a sudden opening. The pressure of the spike was also lower than the stopping point due to hysteresis or system bi-stability.
  • A is the averaging cross-sectional area
  • a 0 is the cross-sectional area before the deformation
  • n is the fitting exponent
  • ⁇ is the dimensionless transmural pressure.
  • the best reported fitting exponent, which captured pressure compensating flow limitation, was n 3/2.
  • the pressure loss from the T-junction to the end of the tube in Fig. 2 is contributed by two components: the resistance of the needle valve and the flexible tube. The pressure loss can be described by
  • u v and A v are the flow velocity and the cross-sectional area inside the needle valve
  • u is the average velocity in the flexible tube
  • k v is the pressure loss coefficient of the needle valve
  • k t is the pressure loss coefficient incurred by the flexible tube.
  • the cross-sectional area ratio can be estimated by .
  • In mode 1 (for small
  • a 0 A v and the flexible tube remains circular in shape at the steady state, so A * A 0 ; in mode 2 (for big diameter tubes), A 0 - 4A V and a significant collapse was observed such that A ⁇ A 0 . Therefore,
  • a modified Starling resistor is disclosed to design a passive, self-regulating valve.
  • a needle valve was introduced in the traditional Starling resistor allowing the flow rate and activation pressure to be controlled separately.
  • the flow limitation phenomenon can be used to self-regulate the flow rate with a very low pumping pressure.
  • a lumped-parameter model was developed to capture the magnitude and trend of the flow limitation observed in experiments at various tube geometries. The trend and magnitude of the experimental results are well predicted by the lumped parameter model.
  • the new architecture disclosed herein is able to control separately the activation pressure and flow rate through the needle valve.
  • the tube geometry determines the activation pressure and the needle valve or flow restrictor determines the flow rate.
  • Experiments were performed to quantify the needle valve's effect and a parametric investigation of tube geometry on flow limitation was performed to clarify the mechanism to adjust the activation pressure.
  • the examined factors include inner diameter, length and wall thickness of the elastic tube.
  • a lumped-parameter model captures the magnitude and trend of the flow limitation.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Automation & Control Theory (AREA)
  • Infusion, Injection, And Reservoir Apparatuses (AREA)

Abstract

L'invention concerne une vanne à autorégulation. La vanne comprend une chambre de pression statique avec un tube déformable élastiquement soutenu dans la chambre de pression statique. Un restricteur est en communication fluidique avec une entrée dans la chambre de pression statique pour un écoulement par le tube déformable. Une tuyauterie relie une source de liquide sous pression, à la fois vers le restricteur et vers une ouverture dans la chambre de pression statique, moyennant quoi le débit dans la vanne reste sensiblement constant avec des variations de pression du liquide sous pression. Dans un mode de réalisation préféré, le restricteur est une soupape à pointeau.
PCT/US2016/062474 2015-11-20 2016-11-17 Vanne à autorégulation basse pression et basse énergie WO2017087638A1 (fr)

Priority Applications (2)

Application Number Priority Date Filing Date Title
US15/320,877 US10254770B2 (en) 2015-11-20 2016-11-17 Low-pressure and low-energy self-regulating valve
US16/376,574 US10761545B2 (en) 2015-11-20 2019-04-05 Low-pressure and low-energy self-regulating valve

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US201562257937P 2015-11-20 2015-11-20
US62/257,937 2015-11-20

Related Child Applications (2)

Application Number Title Priority Date Filing Date
US15/320,877 A-371-Of-International US10254770B2 (en) 2015-11-20 2016-11-17 Low-pressure and low-energy self-regulating valve
US16/376,574 Continuation US10761545B2 (en) 2015-11-20 2019-04-05 Low-pressure and low-energy self-regulating valve

Publications (1)

Publication Number Publication Date
WO2017087638A1 true WO2017087638A1 (fr) 2017-05-26

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Family Applications (1)

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PCT/US2016/062474 WO2017087638A1 (fr) 2015-11-20 2016-11-17 Vanne à autorégulation basse pression et basse énergie

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US (2) US10254770B2 (fr)
WO (1) WO2017087638A1 (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10761545B2 (en) 2015-11-20 2020-09-01 Massachusetts Institute Of Technology Low-pressure and low-energy self-regulating valve
CN114060642A (zh) * 2022-01-12 2022-02-18 艾肯（江苏）工业技术有限公司 一种上水管路用的具有柔性密封结构防水锤装置

Family Cites Families (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2904063A (en) * 1955-09-19 1959-09-15 Gen Motors Corp Flow control mechanism
US3078675A (en) * 1961-11-02 1963-02-26 Arizona Res Foundation Inc Fluid amplifier system
US3429549A (en) * 1966-11-22 1969-02-25 Davol Rubber Co Metering device for flexible tubes
US3640354A (en) * 1969-11-24 1972-02-08 Central Mine Equipment Co Hollow-stem auger head with seal
US3624801A (en) * 1970-04-03 1971-11-30 Grove Valve & Regulator Co Flexible tube valve
US6189857B1 (en) * 1971-04-13 2001-02-20 The United States Of America As Represented By The United States Department Of Energy Fluid-actuated rapid closure valve
CH581793A5 (fr) * 1973-09-03 1976-11-15 Luwa Ag
US4256130A (en) * 1978-08-22 1981-03-17 Pneumafil Corporation Pneumatic valve control for textile machinery blowdown
US5158230A (en) * 1990-08-21 1992-10-27 Curran John R Air flow control apparatus
EP0690254B1 (fr) * 1994-07-01 1998-11-04 HO-Matic AG Robinet à manchon déformable
DE59510556D1 (de) * 1995-12-22 2003-03-20 Festo Ag & Co Vorrichtung zur Erzeugung von periodischen Impulsänderungen in einer Fluid-Strömung, Verfahren zum Betrieb der Vorrichtung und deren Verwendung
US5671774A (en) * 1996-06-18 1997-09-30 Nelson Irrigation Corporation Rate-of-flow control valve
DE19806973A1 (de) * 1998-02-19 1999-08-26 Roediger Anlagenbau Unterdruckventil
US6572259B2 (en) * 2001-04-20 2003-06-03 Burnett Lime Co., Inc. Apparatus and method to dispense a slurry
US7118086B1 (en) * 2005-03-04 2006-10-10 Richway Industries Ltd. Pinch valve with inlet and outlet ports
US7665713B1 (en) * 2006-06-21 2010-02-23 Hunter Industries, Inc. Sleeve valve for residential and commercial irrigation systems
US20080083889A1 (en) * 2006-10-10 2008-04-10 Red Valve Company, Inc. Directly Fluid Operated Pinch Valve
JP5439269B2 (ja) * 2010-02-01 2014-03-12 東洋自動機株式会社 液状物充填機の充填通路開閉装置
US20150267822A1 (en) * 2014-03-18 2015-09-24 Mine Support Products (Pty) Ltd Valve
WO2017087638A1 (fr) 2015-11-20 2017-05-26 Massachusetts Institute Of Technology Vanne à autorégulation basse pression et basse énergie

Non-Patent Citations (19)

* Cited by examiner, † Cited by third party
Title
BERTRAM, C. D.: "Experimental studies of col lapsible tubes", FLOW PAST HIGHLY COMPLIANT BOUNDARIES AND IN COLLAPSIBLE TUBES, 2003, pages 51 - 65
BERTRAM, C. D.; CASTLES, R. J.: "Flow limitation in uniform thick-walled collapsible tubes", JOURNAL OF FLUIDS AND STRUCTURES, vol. 13, no. 3, 1999, pages 399,418
BERTRAM, C. D.; CHEN, W.: "Aqueous flow limitation in a tapered-stiffness collapsible tube", JOURNAL OF FLUIDS AND STRUCTURES, vol. 14, no. 8, November 2000 (2000-11-01), pages 1195 - 1214
BERTRAM, C. D.; ELLIOTT, N. S. J.: "Flow-rate limitation in a uniform thin-walled collapsible tube, with comparison to a uniform thick-walled tube and a tube of tapering thickness", JOURNAL OF FLUIDS AND STRUCTURES, vol. 17, no. 4, March 2003 (2003-03-01), pages 541 - 559
BERTRAM, C. D.; TSCHERRY, J.: "The onset of flow-rate limitation and flow-induced oscillations in collapsible tubes", JOURNAL OF FLUIDS AND STRUCTURES, vol. 22, no. 8, November 2006 (2006-11-01), pages 1029 - 1045
BERTRAM,C.D.; RAYMOND,C.J.; PEDLEY,T.J.: "Mapping of instabilities for flow through collapsed tubes of differing length", JOURNAL OF FLUIDS AND STRUCTURES, vol. 4, no. 2, 1990, pages 125 - 153
BROWER, R. W.; NOORDERGRAAF, A: "Pressure- flow characteristics of collapsible tubes: A reconciliation of seemingly contradictory results", ANNALS OF BIOMEDICAL ENGINEERING, vol. 1, no. 3, March 1973 (1973-03-01), pages 333 - 355
FLAHERTY, J. E.; KELLER, J. B.; RUBINOW, S. I: "Post buckling behavior of elastic tubes and rings with Dopposite sides in contact", SIAM JOURNAL ON APPLIED MATHEMATICS, vol. 23, no. 4, 1972, pages 446 - 455
GAVRIELY, N.; SHEE, T. R.; CUGELL, D. W.; GROTBERG, J. B.: "Flutter in flow-limited collapsible tubes: a mechanism for generation of wheezes", JOURNAL OF APPLIED PHYSIOLOGY, vol. 66, no. 5, 1989, pages 2251 - 2261
GROTBERG, J. B.; JENSEN, O. E.: "Biofluid mechanics in flexible tubes", ANNUAL REVIEW OF FLUID MECHANICS, vol. 36, no. 1, January 2004 (2004-01-01), pages 121 - 147
HEIL, M.; HAZEL, A. L.: "Fluid-Structure Interaction in Internal Physiological Flows", ANNUAL REVIEW OF FLUID MECHANICS, vol. 43, no. 1, January 2011 (2011-01-01), pages 141 - 162
LOW H T ET AL: "PRESSURE/FLOW BEHAVIOUR IN COLLAPSIBLE TUBE SUBJECTED TO FORCED DOWNSTREAM PRESSURE FLUCTUATIONS", MEDICAL AND BIOLOGICAL ENGINEERING AND COMPUTING, SPRINGER, HEILDELBERG, DE, vol. 33, no. 4, 1 July 1995 (1995-07-01), pages 545 - 550, XP000516476, ISSN: 0140-0118 *
LOW, H.; CHEW, Y.: "Pressure/flow relationships in collapsible tubes: effects of upstream pressure fluctuations", MEDICAL AND BIOLOGICAL ENGINEERING AND COMPUTING, vol. 29, 1991, pages 217 - 221
LOW, T. H.; CHEW, Y. T.; WINOTO, S. H.; CHIN, R.: "Pressure/flow behaviour in collapsible tube subjected to forced downstream pressure fluctuations", MEDICAL AND BIOLOGICAL ENGINEERING AND COMPUTING, vol. 33, no. 4, 1995, pages 545 - 550
MORGAN P ET AL: "A mathematical model of flow through a collapsible tube-I. Model and steady flow results", JOURNAL OF BIOMECHANICS, PERGAMON PRESS, NEW YORK, NY, US, vol. 22, no. 11-12, 1 January 1989 (1989-01-01), pages 1263 - 1270, XP026261635, ISSN: 0021-9290, [retrieved on 19890101], DOI: 10.1016/0021-9290(89)90229-7 *
PATTERSON, S. W.; STARLING, E. H.: "On the mechanical factors which determine the output of the ventricles", THE JOURNAL OF PHYSIOLOGY, vol. 48, no. 5, 1914, pages 357 - 379
SHAPIRO, A. H.: "Steady flow in collapsible tubes", JOURNAL OF BIOMECHANICAL ENGINEERING, vol. 99, no. 3, 1977, pages 126
WALSH, C.; SULLIVAN, P. A.; HANSEN, J.; CHEN, L.- W.: "Measurement of wall deformation and flow limitation In a mechanical trachea", JOURNAL OF BIOMECHANICAL ENGINEERING, vol. 117, no. 1, October 2007 (2007-10-01), pages 146
ZIMOCH, P. J.; TIXIER, E.; JOSHI, A.; HOSOI, A. E.; WINTER, A. G.: "Bio-Inspired, low-cost, self-regulating valves for drip irrigation in developing countries", 25TH INTERNATIONAL CONFERENCE ON DESIGN THEORY AND METHODOLOGY, vol. 5, 2013

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10761545B2 (en) 2015-11-20 2020-09-01 Massachusetts Institute Of Technology Low-pressure and low-energy self-regulating valve
CN114060642A (zh) * 2022-01-12 2022-02-18 艾肯（江苏）工业技术有限公司 一种上水管路用的具有柔性密封结构防水锤装置
CN114060642B (zh) * 2022-01-12 2022-04-01 艾肯（江苏）工业技术有限公司 一种上水管路用的具有柔性密封结构防水锤装置

Also Published As

Publication number Publication date
US10761545B2 (en) 2020-09-01
US10254770B2 (en) 2019-04-09
US20180246530A1 (en) 2018-08-30
US20190332128A1 (en) 2019-10-31

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